ATel #9848 announced the latest eruption of the remarkable recurrent nova M31N 2008-12a; the ninth in as many years, and the twelfth reported eruption to date (see Darnley et al. 2016 for full details).

Here we report preliminary results from a Hubble Space Telescope WFC3/UVIS observation of M31N 2008-12a taken between 2016 Dec 17.037 UT and 17.207. These observations occurred around 4.5 days after the discovery of the 2016 eruption (ATel #9848) and were taken as part of proposal 14651. The results here were derived from the data downloaded from the HST archive immediately after the observation.

The nova was detected in both the F645N (Continuum) and F657N (Wide Hα+[N II]) filters with magnitudes of 20.55±0.01 and 19.391±0.007, respectively (both values are Vega magnitudes in the HST/WFC3 flight system).

This photometry is consistent with on-going spectroscopy of the eruption which show strong Hα emission.